Fixed processing of classes in CheckMacrosPass.

We had previously added an early out for declaration contexts but this is not correct for classes since they need to have their preprocessed entities processed by the rest of the pass.

src/Generator/Passes/CheckMacrosPass.cs

@@ -46,7 +46,7 @@ namespace CppSharp.Passes
             if (AlreadyVisited(decl))
                 return false;
 
-            if (decl is DeclarationContext)
+            if (decl is DeclarationContext && !(decl is Class))
                 return true;
 
             var expansions = decl.PreprocessedEntities.OfType<MacroExpansion>();